<template>
  <div class="login_container">
    <div class="login_box">
      <!--头像区域-->
      <div class="touxiang">
        <img src="../assets/logo.png">
      </div>
      <!--表单区域-->
      <el-form ref="loginFormRef"
               class="login_form"
               :model="login_form"
               :rules="loginFormRules">
        <!-- 用户名 -->
        <el-form-item prop="username">
          <el-input v-model="login_form.username"
                    prefix-icon="el-icon-s-custom"></el-input>
        </el-form-item>
        <!-- 密码 -->
        <el-form-item prop="password">
          <el-input v-model="login_form.password"
                    prefix-icon="el-icon-lock"
                    type="password"></el-input>
        </el-form-item>
        <!-- 按扭区域 -->
        <el-form-item class="btns">
          <el-button type="primary"
                     @click="login">登录</el-button>
          <el-button type="info"
                     @click="resetLoginForm">重置</el-button>
        </el-form-item>
      </el-form>
    </div>
  </div>

</template>

<script>
export default {
  data () {
    return {
      // 这是登录表单的数据绑定对象
      login_form: {
        username: 'admin',
        password: '123456'
      },
      // 这是表单的验证规则对象
      loginFormRules: {
        // 验证用户名是否合法
        username: [
          { required: true, message: '请输入用户名', trigger: 'blur' },
          { min: 3, max: 10, message: '长度在 3 到 10个字符', trigger: 'blur' }
        ],
        // 验证密码是否合法
        password: [
          { required: true, message: '请输入密码', trigger: 'blur' },
          { min: 6, max: 15, message: '长度在 6 到 15个字符', trigger: 'blur' }
        ]
      }
    }
  },
  methods: {
    // 点击重置按钮，重置登录表单
    resetLoginForm () {
      this.$refs.loginFormRef.resetFields()
    },
    // 点击登录按钮进行预验证，调用form的validate方法进行全局验证。具体规则见于element form 组件
    login () {
      this.$refs.loginFormRef.validate(async a => {
        if (!a) return
        const { data: res } = await this.$http.post('login', this.login_form)
        if (res.meta.status !== 200) return this.$message.error('登录失败!')
        this.$message.success('登录成功!')
        // 1.将登录成功之后的token，保存到客户端的sessionStorage中
        //   1.1 项目中除了登录之外的其他API接口，必须在登录之后才能访问
        //   1.2 token只应当在当前网站打开期间有效，所以将token保存在sessionStorage中
        window.sessionStorage.setItem('token', res.data.token)
        // 2.通过编程式导航跳转到后台主页，路由地址是 /home
        this.$router.push('/home')
      })
    }
  }
}
</script>

<style lang="less" scoped>
.login_container {
  background-color: #2b4b6b;
  height: 100%;
}
.login_box {
  width: 450px;
  height: 300px;
  background-color: #fff;
  border-radius: 5px;
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  .touxiang {
    width: 110px;
    height: 110px;
    margin: 10px;
    border: 1px solid #eee;
    border-radius: 50%;
    position: absolute;
    left: 50%;
    transform: translate(-50%, -50%);
    background-color: #fff;
    padding: 8px;
    box-shadow: 0 0 8px rgb(106, 187, 187);
    img {
      width: 100%;
      height: 100%;
      border-radius: 50%;
      background-color: #eee;
    }
  }
}
.login_form {
  position: absolute;
  bottom: 0;
  width: 100%;
  padding: 20px;
  box-sizing: border-box;
}
.btns {
  display: flex;
  justify-content: flex-end;
}
</style>
